The antigenic determinants of wheat germ agglutinin will be isolated from cyanogen bran and enzymatic digests. Hybridomas will be prepared from spleen cells of mice immunized with wheat germ agglutinin. The monoclonal hybridoma antibodies will be used to characterize the antigenic determinants and to modify the biological activities of wheat germ agglutinin. Characterization of the target cell involved in driving in vitro differentiation of PFC precursors by lipopolysaccharides will be pursued.